"It's like you're leaving the apartment but taking all the furniture with you!" An indignant Sirius cries to a laughing Remus.
Remus had moved down two desks in Charms, because he couldn't see the blackboard. The outcry arises from Remus returning to their shared desk, only to leave again with his bag, parchment and textbook.
The rest of the class laugh at the spectacle, used to scenes and dramatics from the Marauders. But James doesn't laugh; only watches. Watches intently as Sirius makes a general fuss. Because he is analyzing the real reaction that occurs from the tiny abandonment.
The clench in Sirius' jaws, the spark of panic that flickers across his face momentarily, the resigned slump of the shoulders; all are noticed by James, despite Sirius' efforts. James thinks that it would almost be funny how he would react to James calling him out on the carefully concealed, genuine pain that shadows his movements, and the longing that has replaced the usual light-hearted disposition. Almost.
Because James would be a rubbish friend if he couldn't see the miniscule truth and meaning behind the dramatics – a piss-poor excuse for a best mate if he didn't know that when Remus so much as smiles at anyone else it wasn't as if Remus was breaking his heart, but more like Remus had taken Sirius's heart, smashed it with a toffee-hammer, and then nicked all his vital organs while he was at it. James glimpses over at Lily. Yeah, he knew that feeling.
The most annoying thing of all though is how completely oblivious Remus is to all of this, and that James has no idea of Remus' general standing on people. Boys, girls, diricawls – he simply couldn't gage if Remus felt anything more than friendship to with anything. That would at least be helpful in determining how far up shit creek Sirius was.
But when Remus calls out to Sirius ("Oi, Black! Wanna move in with me?"), patting the empty seat beside him, and Sirius gleefully bounds over like an eager puppy, James takes note of a few other things.
He takes in how Remus shares his textbook with Sirius, even though Sirius has his own and likes to doodle in the margins; observes how Remus flushes when Sirius playfully nudges him, even though Sirius has the most atrociously pointy elbows there are; studies the way Remus patiently explains the tiniest details thoroughly solely for Sirius' sake, even though he could be racing ahead and finishing off homework from other classes.
Another student practises Lumos, and the charm casts glare-spots in Remus' eyes. James joins the dots with his own eyes and fathoms a constellation as Remus laughs at something Sirius says. He isn't sure, but thinks it may be Canis Major.